CN115825436B

CN115825436B - Brucella antibody gel detection reagent and Brucella antibody gel detection method

Info

Publication number: CN115825436B
Application number: CN202211537408.3A
Authority: CN
Inventors: 刘强; 廖南山; 林锋; 柯海婷; 陈琼娣; 汤习锋; 马海波
Original assignee: Zhuhai Langtai Biotechnology Co ltd
Current assignee: Zhuhai Langtai Biotechnology Co ltd
Priority date: 2022-12-01
Filing date: 2022-12-01
Publication date: 2023-10-31
Anticipated expiration: 2042-12-01
Also published as: CN115825436A

Abstract

The invention discloses a Brucella antibody gel detection reagent and a Brucella antibody gel detection method in the technical field of medical detection, wherein the Brucella antibody gel detection reagent comprises microsphere gel, gel buffer solution, anti-human globulin reagent and Brucella antigen reagent, the gel buffer solution takes PBS buffer solution as a substrate, and the PBS buffer solution contains EDTA disodium, bovine serum albumin and PVP. The Brucella antibody gel detection method comprises the steps of adding a mixture of gel buffer solution and anti-human globulin reagent into microsphere gel, centrifuging, dripping blood sample to be detected and Brucella antigen reagent, centrifuging, and judging a detection result according to whether an agglutinate is formed on the upper part of the microsphere gel. The Brucella antibody gel detection reagent has the advantages of high specificity, high sensitivity, strong anti-interference performance, and the detection method is convenient to operate, rapid and accurate.

Description

Brucella antibody gel detection reagent and Brucella antibody gel detection method

Technical Field

The invention relates to the technical field of Brucella detection, in particular to a Brucella antibody gel detection reagent and a Brucella antibody gel detection method.

Background

Brucellosis (Brucellosis for short) is an infectious disease which is caused by invasion of Brucellosis into the body and is characterized by fever and abortion, and seriously threatens the life health of people and various animals. Brucella mainly invades the reproductive system of animals, causes abortion and infertility, and brings about serious economic loss. After people have been infected with brucella disease by contacting the blood, placenta, embryo or uterine secretions of the diseased animal, or people eat products with brucella bacteria animals, it is often difficult to cure, serious people even lose labor and fertility, thus causing serious public health problems.

The detection method for diagnosing brucellosis at present mainly comprises the following steps: tiger red plate (RB) agglutination method, standard agglutination test tube (SAT) method, indirect anti-human ball method (index Coombs) and Immunocapture-agglutination method. The detection methods for diagnosing brucellosis are all serum immunological methods, and red blood cells need to be separated from blood samples to be detected. Wherein, the tiger red plate (RB) method and the standard agglutination test tube (SAT) method can only detect complete antibodies, and can not detect incomplete antibodies, and the false negative probability is high (the sensitivity is low); the indirect anti-human ball method can detect incomplete antibodies, but requires repeated centrifugal washing, and has long detection time; reagents used in the immunocapture method are expensive, and in addition, the detection time is 18 to 24 hours, so that the requirement of rapid diagnosis is difficult to achieve.

Therefore, in order to overcome the shortcomings of the brucellosis detection method, development of a brucellosis detection technology with high sensitivity, good specificity and convenient and rapid operation is needed.

Disclosure of Invention

Aiming at the technical problems in the prior art, the Brucella antibody gel detection reagent provided by the invention has the advantages of good specificity and high sensitivity, and the Brucella antibody gel detection method is convenient to operate, rapid and accurate, and the blood sample to be detected can be serum or whole blood.

In order to solve the technical problems, the technical scheme of the invention is as follows:

the Brucella antibody gel detection reagent provided by the invention comprises the following components: microsphere gel, gel buffer, antihuman globulin reagent, brucella antigen reagent, its characterized in that: the gel buffer solution takes PBS buffer solution as a substrate, and EDTA disodium, bovine serum albumin and PVP are added into the PBS buffer solution.

Preferably, the microgel is a sephadex microgel, and the particle size of the sephadex microgel ranges from 30 to 80 microns.

Preferably, the PBS buffer solution contains disodium hydrogen phosphate, monopotassium phosphate, sodium chloride and potassium chloride, wherein the concentration range of the disodium hydrogen phosphate is 9-10.5 mM, the concentration range of the monopotassium phosphate is 1.5-2.5 mM, the concentration range of the potassium chloride is 2-3 mM, the concentration range of the sodium chloride is 130-140 mM, and the PH value range of the PBS buffer solution is as follows: 7.2 to 7.4.

Preferably, the molecular weight of PVP is 8000-40000.

Preferably, 0.5-1.5 g of bovine serum albumin, 1.5-3 g of disodium EDTA and 0.2-0.5 g of PVP are added into 100ml of PBS buffer, and the PH value of the gel buffer is 6.8-7.2.

Preferably, the gel buffer contains 1-1.5 g of bovine serum albumin, 2-3 g of disodium EDTA and 0.2-0.4 g of PVP in every 100ml of PBS buffer, and the pH value of the gel buffer is 7.0.

Preferably, the volume ratio of the gel buffer to the anti-human globulin agent is 1:1 to 7:1.

preferably, the brucella antigen reagent is a brucella antigen dyed by tiger red is added into PBS buffer solution, and the concentration of the brucella antigen dyed by tiger red is 1% -4%.

The Brucella antibody gel detection method using the Brucella antibody gel detection reagent provided by the invention comprises the following steps:

s11: the anti-human globulin reagent is added into the gel buffer solution to prepare a mixture, and the volume ratio of the gel buffer solution to the anti-human globulin reagent is 1:1 to 7:1, a step of;

s21: the mixture is added into the microsphere gel to prepare a gel matrix, and the volume ratio of the microsphere gel to the mixture is 8:3, a step of;

s31: adding 30 microliters of the gel matrix in the step S21 into Kong Zhuzhong of a microcolumn gel card, and centrifuging the microcolumn gel card;

s41: dropwise adding whole blood and the brucella antigen reagent into the hole column of the microcolumn gel card after the centrifugation in the step S31;

s51: centrifuging the microcolumn gel card in the step S41;

s61: judging result:

when red blood cells in the whole blood are deposited at the bottom of the hole column, and an agglutinate is formed at the upper part of microsphere gel in the hole column, judging positive;

and judging as negative when the red blood cells in the whole blood are deposited at the bottom of the hole column and the aggregates are not formed on the upper part of the microsphere gel in the hole column.

s12: the anti-human globulin reagent is added into the gel buffer solution to prepare a mixture, and the volume ratio of the gel buffer solution to the anti-human globulin reagent is 1:1 to 7:1, a step of;

s22: the mixture is added into the microsphere gel to prepare a gel matrix, and the volume ratio of the microsphere gel to the mixture is 8:3, a step of;

s32: adding 30 microliters of the gel matrix in the step S22 into Kong Zhuzhong of a microcolumn gel card, and centrifuging the microcolumn gel card;

s42: dropwise adding a blood sample to be tested and the brucella antigen reagent into the hole column of the microcolumn gel card after the centrifugation in the step S32;

s52: centrifuging the microcolumn gel card in the step S42;

s62: judging result:

positive is judged when the upper part of the microsphere gel in the pore column forms an agglutinate;

and judging as negative when the upper part of the microsphere gel in the pore column does not form an agglutinate.

The beneficial effects of the invention are as follows:

the Brucella antibody gel detection reagent has the advantages of good specificity, high sensitivity and strong anti-interference performance, and the Brucella antibody gel detection method using the detection reagent is convenient to operate, rapid and accurate, and not only can use serum as a sample to be detected, but also can use whole blood as the sample to be detected. When whole blood is used as a sample to be detected, the influence of red blood cells and fibrinogen is completely avoided, the detection result is easy to judge, the bidirectional inhibition is realized, and the antigen and the antibody of brucella are ensured to have enough agglutination strength. The invention has low requirements on the skills of operators, simple detection program and low cost.

Drawings

FIG. 1 is a schematic flow chart of the detection of Brucella antibodies using whole blood according to the present invention.

FIG. 2 is a schematic diagram of the present invention for Brucella antibody detection using whole blood.

FIG. 3 is a graph showing the results of detection of Brucella antibodies using whole blood.

FIG. 4 is a schematic flow chart of the detection of Brucella antibodies using serum according to the present invention.

FIG. 5 is a schematic diagram of the detection of Brucella antibodies using serum according to the present invention.

FIG. 6 is a graph showing the results of detection of Brucella antibodies using serum according to the present invention.

Detailed Description

In order that those skilled in the art can better understand the technical solutions provided by the present invention, the following describes the present invention in detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.

The Brucella antibody gel detection reagent comprises microsphere gel, gel buffer solution, anti-human globulin reagent and Brucella antigen reagent.

The microsphere gel plays a role of molecular sieve in Brucella detection, and gaps among the microsphere gel can allow red blood cells to pass through with non-aggregated Brucella antigens and can also prevent the aggregation of the Brucella antigens and antibodies from passing through. If the diameter range and average diameter of the microgel are too small, red blood cells and non-aggregated Brucella antigen are hardly accumulated in the upper part of the gel through the gel gap, resulting in a falseA positive result; if the diameter range and the average diameter are too large, the aggregation strength of the aggregates of the Brucella antibody and the Brucella antigen is lowered, and it is difficult to form aggregates on the upper portion of the gel, resulting in false negative results. The cross-linked dextran microsphere gel had a particle size range of 30 to 80 microns and an average particle size (50+5) And the microsphere gel is detected by selecting the cross-linked dextran microsphere gel with a proper particle size range, so that misjudgment can be effectively avoided.

When the PBS buffer solution is prepared, disodium hydrogen phosphate, monopotassium hydrogen phosphate, sodium chloride and potassium chloride are mixed and prepared, and the powder of the compounds can be mixed and then dissolved, or the solutions of the compounds can be mixed, wherein the concentration range of the disodium hydrogen phosphate in the PBS buffer solution is 9-10.5 mM, the concentration range of the monopotassium hydrogen phosphate is 1.5-2.5 mM, the concentration range of the potassium chloride is 2-3 mM, the concentration range of the sodium chloride is 130-140 mM, and the pH value range of the prepared PBS buffer solution is as follows: 7.2 to 7.4.

When the gel buffer is prepared, PBS buffer is taken as a substrate, and EDTA disodium, bovine serum albumin, PVP and the like are added into the PBS buffer. When preparing the gel buffer, the prepared gel buffer needs to contain 0.5-1.5 g of bovine serum albumin, 1.5-3 g of disodium EDTA and 0.2-0.5 g of PVP in every 100ml of PBS buffer, and the PH value of the prepared gel buffer is 6.8-7.2. In order to meet the requirement that the pH value of the gel buffer solution is 7.0 as much as possible, 1 to 1.5 grams of bovine serum albumin, 2 to 3 grams of disodium EDTA and 0.2 to 0.4 gram of PVP are contained in every 100ml of PBS buffer solution. The EDTA disodium is used as an anticoagulant to effectively prevent fibrinogen from being converted into fibrin, and further can effectively prevent the coagulation of red blood cells in a blood sample. In addition, bovine serum albumin can improve the lubricity of the microsphere gel, so that unagglutinated red blood cells and Brucella antigen can pass through gaps between the microsphere gels and can be smoothly deposited on the lower parts of the microsphere gels, thereby avoiding false positives. To further improve the lubricity of the microsphere gel, bovine serum albumin may be added to the PBS buffer, and PVP may also be added in an appropriate amount. The molecular weight of PVP is 8000-40000, and the molecular weight of PVP can be 8000-24000. Under the action of centrifugal force, PVP can enable the red blood cells and brucella antigens which are not aggregated to smoothly pass through gaps among the microgels so as to be precipitated at the lower parts of the microgels, thereby avoiding false positive and bidirectional; PVP can also properly increase the viscosity of the gel buffer, thereby enhancing the aggregation strength of Brucella antigen and antibody.

When preparing the anti-human globulin reagent, selecting an anti-human globulin reagent solution produced by mill ipore company, wherein the volume ratio of the gel buffer solution to the anti-human globulin reagent solution is 1:1 to 7:1. In detection, a quantitative anti-human globulin reagent solution is added into a gel buffer solution and mixed, and can be prepared in advance for standby.

When the brucella antigen reagent is prepared, the brucella antigen is dyed by using the tiger red dye, and the brucella antigen dyed by the tiger red is added into the PBS buffer solution, wherein the concentration of the brucella antigen dyed by the tiger red is 1-4%. For obvious color development, the concentration of the Brucella antigen stained with tiger red may be 2% -4%. Brucella antigens can be stained with tiger red dye, or other stains can be used.

The prepared microsphere gel, gel buffer solution, anti-human globulin reagent and brucella antigen reagent can be independently packaged in a reagent bottle, or the microsphere gel and the gel buffer solution can be prepared and packaged in a test tube or a plurality of hole columns filled in a micro-column gel card, and the openings of the hole columns are sealed by aluminum foils.

The invention uses the Brucella antibody gel detection reagent to detect Brucella, and the blood sample to be detected is whole blood or serum, and can be detected in test tubes, microcolumn gel cards and other experimental containers. When the detection is carried out by using the microcolumn gel card, the microsphere gel, the gel buffer solution and the antihuman globulin reagent can be mixed together, and the mixture is added into a hole column of the microcolumn gel card after full mixing; or firstly, putting microsphere gel into a hole column of a microcolumn gel card, then injecting a certain amount of gel buffer solution according to the requirement to fully mix, then adding an antihuman globulin reagent according to the volume ratio, and fully mixing by centrifugation; and adding a blood sample to be detected and a brucella antigen reagent into the centrifuged Kong Zhuzhong, centrifuging the microcolumn gel card, and judging the detection result by observing whether the upper part of the microsphere gel in the microcolumn gel card hole column forms an agglutinate or not.

The specific embodiment of the invention is to detect brucellosis in a hole column of a microcolumn gel card by using the brucellosis antibody gel detection reagent. The specific detection method comprises the following steps:

example 1:

as shown in FIG. 1, a schematic flow chart of Brucella antibody detection using whole blood is shown. When the detection is carried out by using a microcolumn gel card, adding the microsphere gel, the gel buffer solution and the anti-human globulin reagent into a pore column of the gel card for mixing, and then adding whole blood and brucella antigen reagent for detection, wherein the specific steps comprise:

s11: adding an antihuman globulin reagent into a gel buffer solution to prepare a mixture, wherein the volume ratio of the gel buffer solution to the antihuman globulin reagent is 1:1 to 7:1, a step of;

s21: adding the mixture obtained in the step S11 into microsphere gel to prepare a gel matrix, wherein the volume ratio of the microsphere gel to the mixture is 8:3, a step of;

s31: adding 30 microliters of the gel matrix in the step S21 into Kong Zhuzhong of the microcolumn gel card, and putting the microcolumn gel card into a centrifuge for centrifugation;

s41: 1-3 drops of whole blood and 1-3 drops of brucella antigen reagent are added into the corresponding hole column of the microcolumn gel card after the centrifugation in the step S31; to avoid that too many red blood cells influence the detection result, 1 drop of whole blood can be added into the hole column; to save materials, 1 drop of brucella antigen reagent can be added;

s51: putting the microcolumn gel card in the step S41 into a card type centrifuge for centrifugation under the condition of 800g for 20min;

s61: judging result:

when red blood cells in the whole blood are deposited at the bottom of the hole column, and red aggregates are formed at the upper part of microsphere gel in the hole column, the red blood cells are judged to be positive;

red blood cells in whole blood are negative when they are deposited at the bottom of the well column and red aggregates are not formed at the upper part of the microgel in the well column.

When red blood cells in whole blood pass through the gaps of the microgel and are deposited on the lower part of the microgel in the pore column, that is, the red blood cells are deposited on the bottom of the pore column, it is indicated that the added blood sample is whole blood or anticoagulated whole blood.

The judgment result in step S61 is specifically the detection principle shown in fig. 2. The detection result is judged mainly by observing whether red blood cells in the gel card of the microcolumn are deposited at the bottom of the hole column and whether aggregates are formed at the upper part of the microgel in the hole column. Whole blood or anticoagulated whole blood is added into a hole column of a micro-column gel card with a gel matrix, and when complete antibodies of brucella exist in a blood sample to be detected, the added brucella antigen and the complete antibodies of the brucella are combined to form an agglutinate at the upper part of microsphere gel in the hole column. Since the agglutinate is blocked at the upper part thereof by the microgel, red blood cells and/or excessive non-agglutinated brucella antigen are deposited at the lower part of the microgel or at the bottom of the column through the gaps between the microgels under the action of centrifugal force, and the detection result is judged as positive as shown in (a) of fig. 2. When the blood sample to be detected contains the incomplete antibody of brucella, the added brucella antigen and the incomplete antibody of brucella form smaller agglutinates after being combined, and large agglutinates are further formed at the upper part of the microsphere gel in the pore column through the bridging action of the anti-human globulin reagent. Since the agglutinate is blocked at the upper part thereof by the microgel, red blood cells and/or excessive non-agglutinated brucella antigen are deposited at the lower part of the microgel or at the bottom of the column through the gaps between the microgels under the action of centrifugal force, and the detection result is judged positive as shown in (b) of fig. 2. When no Brucella antibody exists in the blood sample to be detected, the added Brucella antigen cannot be aggregated alone, under the action of centrifugal force, red blood cells and/or Brucella antibodies are deposited at the lower part of the microgel or at the bottom of the hole column through gaps among the microgels, and the upper part of the microgel in the hole column cannot form an aggregate, and the detection result is judged to be negative, as shown in (c) of fig. 2.

When whole blood or anticoagulated whole blood is added into a column with microgel, as the brucella antigen is dyed by tiger red, red agglutinate is formed on the upper part of the microgel in the column by observing the brucella antigen and antibody by naked eyes, red blood cells and/or non-agglutinated brucella antigen are deposited on the lower part of the microgel in the column or on the bottom of the column by centrifugation, so that the bottom of the column is red, and red agglutinate is formed on the upper part of the microgel in the column, the column is judged to be positive; red color appears at the bottom of the well and red agglutinate is judged to be negative when red blood cells and/or non-agglutinated brucella antigen are deposited on the lower part of the microgel in the well or on the bottom of the well, and red agglutinate is not formed on the upper part of the microgel in the well.

As shown in fig. 3, further validation of the interpretation of the results of brucella antibody detection using whole blood was performed. In order to further verify the accuracy of the above-described judgment result, false positives and false negatives are avoided. Specifically, after the microcolumn gel card is centrifuged in step S51, it is observed in step S61 whether or not aggregates are present in the column 1 of the gel card. After centrifugation, red blood cells 4 are all deposited at the bottom of the pore column 1, and when red agglutinate 2 formed by complete combination of brucella antigen and brucella antibody is formed at the top of the microsphere gel 3, the agglutination intensity is judged to be '4+'; when the aggregate 2 is mainly concentrated on the top of the microgel 3, but a small amount of aggregate falls from the top of the microgel 3, the aggregation strength is judged as "3+". Therefore, when the agglutination intensities are "4+", "3+", the detection result can be judged positive, as shown in FIG. 3 (a). When small aggregates are scattered in the column 1 and dispersed throughout the microgel 3, the aggregation strength is judged as "2+"; when small aggregates are dispersed in the column 1 and in the lower half of the microgel 3, the aggregation strength is judged as "1+"; when a small amount of small agglutinate or non-agglutinated Brucella antigen 5 and red blood cells 4 are deposited at the bottom of the well column through the lower portion of the microgel 3, the agglutination intensity is judged as "-". Therefore, when the agglutination intensity is "2+", "1+", "-", the detection result can be judged negative. If the agglutination is negative or weak, the microsphere gel 3 is judged to be "bidirectional" if there is a pale band of agglutination 6 on top. In the case of individual "bi-directional", there is also a very small amount of small agglutinates or non-agglutinated brucella antigen 5 and erythrocytes 4 deposited at the bottom of the column by the microgel 3. When "bidirectional" occurs, the disappearance of the aggregation band 6 can be observed by adding an appropriate amount of PVP, and further, the determination can be made based on the presence or absence of aggregates. When negative, bi-directional occurs, as shown in (b) of fig. 3.

Example 2:

FIG. 4 is a schematic flow chart of the detection of Brucella antibodies using serum. When the detection is carried out by using a microcolumn gel card, adding the microsphere gel, the gel buffer solution and the anti-human globulin reagent into a pore column of the gel card for mixing, and then adding serum and the brucella antigen reagent for detection, wherein the specific steps comprise:

s12: adding an antihuman globulin reagent into a gel buffer solution to prepare a mixture, wherein the volume ratio of the gel buffer solution to the antihuman globulin reagent is 1:1 to 7:1, a step of;

s22: the mixture is added into microsphere gel to prepare gel matrix, and the volume ratio of the microsphere gel to the mixture is 8:3, a step of;

s32: adding 30 microliters of the gel matrix in the step S22 into Kong Zhuzhong of the microcolumn gel card, and centrifuging the microcolumn gel card;

s42: dropwise adding 1-3 drops of serum and 1-3 drops of brucella antigen reagent into a hole column of the microcolumn gel card after the centrifugation in the step S32; 1 drop of serum and 1 drop of brucella antigen reagent are generally dripped, so that the observation is convenient;

s52: putting the microcolumn gel card in the step S42 into a card type centrifuge for centrifugation under the condition of 800g for 20min;

s62: judging result:

when the upper part of the microsphere gel in the pore column forms red agglutinate, the positive result is judged;

a negative is determined when red aggregate is not formed on the upper portion of the microgel in the well.

The judgment result in step S62 is specifically the detection principle shown in fig. 5. The detection result is mainly judged by observing whether the upper part of microsphere gel in a gel clamping hole column of the microcolumn forms an agglutinate or not. When the serum to be detected contains complete antibodies of brucella, the added brucella antigen and the complete antibodies of brucella are combined to form an agglutinate, as shown in (a) of fig. 5; when the serum to be tested contains incomplete antibodies of brucella, the added brucella antigen is originally combined with the incomplete antibodies of brucella to form smaller aggregates, and then large aggregates are formed by the bridging action of the anti-human globulin reagent, as shown in (b) of fig. 5. Since brucella antigen had been stained with tiger red, it was easily judged by visual observation of whether or not red aggregates were formed on the upper portion of Kong Zhuzhong microsphere gel. When the upper part of the microsphere gel in the pore column forms red agglutinate, the result is positive, as shown in (a) and (b) of FIG. 5; when red aggregates are not formed on the upper portion of the microgel in the well column, the result is negative, as shown in FIG. 5 (c).

When the added blood sample to be detected is serum, if antibodies exist in the serum, the upper part of the microsphere gel forms an agglutinate, and the detection result is judged to be positive; when no antibody is added to the serum, the upper part of the microsphere gel does not form an agglutinate, and the detection result is judged as negative.

As shown in fig. 6, further validation of the interpretation of the results of brucella antibody detection using serum was performed. In order to further verify the accuracy of the above-described judgment result, false positives and false negatives are avoided. Specifically, after the microcolumn gel card is centrifuged in step S52, aggregates in the column 1 of the gel card are observed in step S62. When the aggregate 2 in which the brucella antigen and the brucella antibody were completely bound was formed on top of the microgel 3, the aggregation strength was judged as "4+"; when the aggregates 2 are mainly concentrated on the top of the microgel 3, a little of the aggregates fall from the top of the microgel 3, and the aggregation strength is judged as "3+". Therefore, when the agglutination intensities were "4+" and "3+" as shown in FIG. 6 (a), the detection results were positive. When the aggregates are dispersed in the column 1 and dispersed throughout the microgel 3, the aggregation strength is judged as "2+"; when the aggregates are scattered and concentrated mainly in the lower half of the microgel 3, the aggregation strength is judged as "1+"; when there was a small amount of agglutinated or unagglutinated Brucella antigen 5, it was settled at the bottom of the microgel 3, and the agglutination intensity was judged as "-". Therefore, when the agglutination intensity is "2+", "1+", "-", the detection result can be judged negative. If negative or weak agglutination occurs, the microsphere gel 3 is judged to be "bi-directional" with a light band of agglutination 6 on top. In the case of individual "bi-directional", there is also a very small amount of small agglutinate or unagglutinated Brucella antigen 5 deposited at the bottom of the column via the microgel 3. When the bidirectional flow occurs, the aggregation band 6 may be eliminated by adding an appropriate amount of PVP, and further, it may be judged whether or not aggregates are present. When the coagulation-negative and bidirectional effects occur, the method is shown in FIG. 6 (b).

Therefore, whether the blood sample to be detected is serum, whole blood or anticoagulated whole blood or not can be rapidly judged whether the detection result is positive or not mainly by observing whether red agglutinate appears on the upper part of microsphere gel in the pore column obviously or not.

In order to further verify the judgment result of the detection method, the following groups of comparison experiments are performed:

comparative experiment 1

Formulation of gel buffer: to 100ml PBS buffer, 0.5g bovine serum albumin, 2 g disodium EDTA, and no PVP were added, the pH of the buffer was 7.0.

The brucella antigen concentration was 2%, and the specific detection method was as in example 1:

s11: adding an antihuman globulin reagent into a gel buffer solution to prepare a mixture, wherein the volume ratio of the gel buffer solution to the antihuman globulin reagent is 1:1

S21: the mixture is added into microsphere gel to prepare gel matrix, and the volume ratio of the microsphere gel to the mixture is 8:3, a step of;

s31: adding 30 microliters of the gel matrix in the step S21 into Kong Zhuzhong of the microcolumn gel card, and centrifuging the microcolumn gel card;

s41: 2.5 microliters of negative control anticoagulated whole blood was added to 50 microliters of PBS buffer and mixed well.

S51: adding 25 microliters of S41 diluted negative quality control anticoagulated whole blood and 25 microliters of Brucella antigen suspension into a hole column of the microcolumn gel card after the centrifugation in the step S31;

s61: putting the microcolumn gel card in the step S51 into a card type centrifuge for centrifugation under the condition of 800g for 20min;

after centrifugation, bidirectional generation is found, and false positive misjudgment is easily caused.

Comparative example 2

Formulation of gel buffer: to 100ml PBS buffer, 0.5g bovine serum albumin, 0.2 g PVP, molecular weight 10000,2 g disodium EDTA, pH 7.0 were added.

The concentration of the brucella antigen is 2%, other steps such as a comparison experiment (I), red blood cells and the brucella antigen are precipitated at the bottom of the hole column after centrifugation, and the result is clear and can be judged.

Comparative experiment (iii):

to 100ml of PBS buffer, 1 g of bovine serum albumin, 2 g of disodium ethylenediamine tetraacetate, 0.2 g of PVP having a molecular weight of 10000 was added to prepare a gel buffer having a pH of 7.0.

A suspension of tiger red-stained brucella antigen was prepared, the concentration of tiger red-stained brucella antigen being 2%.

When preparing the antihuman globulin reagent, the volume ratio of the gel buffer solution to the antihuman globulin reagent is 1:1 to 7:1. To verify the effect of the volume ratio of anti-human globulin reagent and gel buffer on the experimental results, the following experiments were designed:

for each volume ratio, 8 test tubes and corresponding 8 Kong Weizhu gel cards were prepared. The first tube was filled with 100. Mu.l PBS buffer and the second to eighth tubes were each filled with 50. Mu.l PBS buffer. The first to seventh test tubes are used for diluting the positive anticoagulated whole blood, and the eighth test tube is used for diluting the negative anticoagulated whole blood. 5 microliters of positive anticoagulated whole blood was added to the first tube and mixed with PBS buffer, then 50 microliters were removed to the second tube and mixed well in the second tube, and so on. An eighth tube was added with 2.5. Mu.l of negative anticoagulated whole blood and then mixed well. Using a pipette, 25 microliters of the mixture was removed from each tube and added to the corresponding well in the microcolumn gel card, after which 25 microliters of brucella antigen suspension was added to each well using a pipette. Finally, putting the microcolumn gel card into a card type centrifuge for centrifugation under the following conditions: 800g for 20min. The titer of whole blood in the first well was 1/40, and the titers of whole blood diluted by a double ratio in the second to seventh wells.

Interpretation of the results: after centrifugation, the red blood cells all settled at the bottom of the well column. When the agglutinate is completely on top of the microsphere gel, the agglutination intensity is judged to be 4+; when the aggregates are mainly concentrated on the top of the microsphere gel, a little of the aggregates fall from the top of the gel, and the aggregation strength is judged to be 3+; when the aggregates are dispersed in the whole microsphere gel in the pore column, the aggregation strength is judged to be 2+; when the aggregates are mainly concentrated in the lower half of the microgel, the aggregation strength is judged to be 1+; when the agglutinate is completely settled at the bottom of the microsphere gel column, the agglutination intensity is judged as negative. If negative or weak agglutination occurs, the gel is judged to be bidirectional with a light band on top. If the aggregation strength is 4+ or 3+, positive results are obtained.

In preparing the anti-human globulin reagent, to verify that the volume ratio of gel buffer to anti-human globulin reagent is 1:1 to 7:1, a few groups of experiments were performed:

(1) When the reagent is the anti-human globulin reagent, the experimental detection results are as follows:

a first hole

Second hole

Third hole

Fourth hole

Fifth hole

Sixth hole

Seventh hole

Eighth hole

1/40

1/80

1/160

1/320

1/640

1/1280

1/2560

-

4+

3+

2+

++ (two-way)

(two-way)

As shown in the above table, when the anti-human globulin reagent is used for all, the titer is 1/320 to 4+, and then the agglutination intensity is reduced, but the titer is 1/2560 and negative, the bidirectional effect occurs, so that false positive misdiagnosis is easily caused.

(2) When anti-human globulin agent: the volume ratio of the gel buffer is 1:1, the experimental detection results are as follows:

a first hole

Second hole

Third hole

Fourth hole

Fifth hole

Sixth hole

Seventh hole

Eighth hole

1/40

1/80

1/160

1/320

1/640

1/1280

1/2560

-

4+

3+

2+

+

-

As shown in the above table, when anti-human globulin agent: the volume ratio of the gel buffer is 1: in 1, there was no substantial decrease in the aggregation strength compared to the anti-human globulin agent, but there was no bidirectional production at 1/2560 and negative. Mainly EDTA disodium in gel buffer solution can effectively inhibit fibrinogen in anticoagulated whole blood from being converted into fibrin, and can prevent red blood cells from generating tiny aggregates; and meanwhile, bovine serum albumin and PVP can enable the surface of the microsphere gel to be smoother, are more beneficial to the deposition of erythrocytes and tiger antigens without agglutination to the bottom, and inhibit the bidirectional generation.

(3) When anti-human globulin agent: the volume ratio of the gel buffer is 1:3, the experimental detection results are as follows:

a first hole

Second hole

Third hole

Fourth hole

Fifth hole

Sixth hole

Seventh hole

Eighth hole

1/40

1/80

1/160

1/320

1/640

1/1280

1/2560

-

4+

3+

2+

+

-

As shown in the above table, when anti-human globulin agent: the volume ratio of the gel buffer is 1:3, the aggregation strength was lowered to 3+ at 1/320. Mainly because when incomplete antibodies in plasma and brucella antigens combine into small agglutination products, anti-human globulin agents cause these small agglutination products to form large agglutination products by bridging. Without sufficient anti-human globulin agent, these small agglutination products tend to fall off during centrifugation, reducing the agglutination strength.

(4) When anti-human globulin agent: the volume ratio of the gel buffer is 1:7, the experimental detection results are as follows:

a first hole

Second hole

Third hole

Fourth hole

Fifth hole

Sixth hole

Seventh hole

Eighth hole

1/40

1/80

1/160

1/320

1/640

1/1280

1/2560

-

4+

3+

2+

+

-

When anti-human globulin agent: the volume ratio of the gel buffer is 1:7, the aggregation strength is further lowered. At 1/160, the titer is 3+, mainly because the anti-human globulin reagent is too small and the ability to detect incomplete antibodies is further reduced.

Therefore, the volume ratio of gel buffer to antihuman globulin reagent is formally selected by the above experiment to be 1:1 to 7:1.

comparative experiment (four):

anti-human globulin agent in comparative experiment (three) was used: the volume ratio of gel buffer was 1:7, except that the gel buffer formulations were different. To 100ml PBS buffer, 1 g bovine serum albumin, 2 g disodium ethylenediamine tetraacetate and 0.4 g PVP with molecular weight 10000 were added to prepare a gel buffer with pH of 7.0. The experimental detection results are as follows:

a first hole

Second hole

Third hole

Fourth hole

Fifth hole

Sixth hole

Seventh hole

Eighth hole

1/40

1/80

1/160

1/320

1/640

1/1280

1/2560

-

4+

3+

2+

+

-

As shown in the above table, increasing the amount of PVP in the gel buffer increased the third well agglutination intensity from original 3+ to 4+.

In summary, to keep positive high potency and inhibit bi-directional production, the volume ratio of anti-human globulin reagent to gel buffer solution is 1:1. thus, enough anti-human globulin reagent is used for bridging the coagulation products of the incomplete antibody and the brucella antigen, and simultaneously disodium EDTA, bovine serum albumin and PVP in the buffer solution can effectively inhibit the bidirectional generation.

In addition, according to the document Evaluation of a New and Rapid Serologic Test for Detecting Brucellosis: brucella Coombs Gel Test, positive results were obtained when the serum titer was 1/160 or more and the agglutination intensity was 3+ or more. To simplify the test procedure, the following experiments were designed:

and (3) extracting whole blood of the patient to be detected by using the EDTA tube, and then reversing the EDTA tube to uniformly mix the EDTA and the whole blood. 2 ml of PBS buffer was added to a test tube, and then the anticoagulated whole blood was sucked up using a dropper, and a drop of the anticoagulated whole blood was added to the test tube and mixed well. Adding a drop of anticoagulated whole blood diluted by PBS into the corresponding hole in the microcolumn gel card by using a dropper, adding a drop of brucella antigen suspension into the corresponding hole by using the dropper, and finally centrifuging. The volume of one drop of the dropper is about 30 microliters, so that the titer of the whole blood is about 1/140, which is close to 1/160 of the literature.

Use of anti-human globulin agent: the volume ratio of the gel buffer is 1:1, wherein the gel buffer is prepared by adding 1 gram of bovine serum albumin, 2 grams of disodium ethylenediamine tetraacetate, 0.2 gram of PVP and the PVP molecular weight is 10000 into 100ml of PBS buffer, and the pH value of the gel buffer is 7.0. Preparing a Brucella antigen suspension dyed by tiger red, wherein the concentration of the Brucella antigen dyed by tiger red is 2%, the patient to be tested is 16 people, and in 16 total pore columns of two microcolumn gel cards, PBS is dripped into each pore column by using a dropper to dilute anticoagulated whole blood. The experimental detection results are as follows:

as shown in the table above, the positive agglutination intensity is 4+, and the negative is not generated in two directions, thus proving that the method is simple and effective. Later, the tiger red plate agglutination method was used for re-examination and verification, 7 out of 16 patients were positive, 9 were negative, and the positive patient No. 4, which was inconsistent with the detection result of the method, had history of infection by follow-up inquiry of the hospital.

Compared with the literature record of the serological detection method, when the whole blood is used, the step of centrifugation after blood drawing is omitted, and the uniform mixing of the Brucella antigen suspension and the sample to be detected is omitted before the blood is added into the microsphere gel card, and meanwhile, the influence of fibrinogen in red blood cells and blood plasma can be completely avoided. The method is expected to be widely popularized in pastoral areas, and a herder only needs to use an EDTA tube to extract whole blood of a patient to be tested, and the consumable used is a dropper. Compared with a pipetting gun, the pipetting gun is operated by a professional, the dropper is a popular consumable, and a great deal of time is not required to be spent for teaching the herdsmen how to use the card, so that a great deal of manpower and material resources are saved.

The Brucella antibody gel detection reagent has high specificity, high sensitivity and strong anti-interference performance, and the Brucella antibody gel detection method using the detection reagent is convenient to operate, rapid and accurate. Not only serum but also whole blood may be used as a sample to be tested. When whole blood is used as a sample to be detected, the influence of red blood cells and fibrinogen is completely avoided, the detection result is easy to judge, the detection method inhibits bidirectional, and the antigen and the antibody of brucella are ensured to have enough agglutination strength. The invention can use dropper consumable to sample and add sample, has low requirement on the skill of operators, can detect in any place except hospitals, and has simple detection procedure and low cost.

The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

1. The Brucella antibody gel detection reagent comprises microsphere gel, gel buffer solution, anti-human globulin reagent and Brucella antigen reagent, and is characterized in that: the gel buffer takes PBS buffer as a substrate, and EDTA disodium, bovine serum albumin and PVP are added into the PBS buffer;

the gel buffer solution is prepared by adding 0.5-1.5 g of bovine serum albumin, 1.5-3 g of disodium EDTA and 0.2-0.5 g of PVP into 100ml of PBS buffer solution, and the pH value of the gel buffer solution is 6.8-7.2.

2. The brucella antibody gel detection reagent according to claim 1, wherein: the microsphere gel is a cross-linked dextran microsphere gel, and the particle size range of the cross-linked dextran microsphere gel is 30-80 microns.

3. The brucella antibody gel detection reagent according to claim 1, wherein: the PBS buffer solution contains disodium hydrogen phosphate, monopotassium phosphate, sodium chloride and potassium chloride, wherein the concentration range of the disodium hydrogen phosphate is 9-10.5 mM, the concentration range of the monopotassium phosphate is 1.5-2.5 mM, the concentration range of the potassium chloride is 2-3 mM, the concentration range of the sodium chloride is 130-140 mM, and the pH value range of the PBS buffer solution is as follows: 7.2 to 7.4.

4. The brucella antibody gel detection reagent according to claim 1, wherein: the molecular weight of PVP is 8000-40000.

5. The brucella antibody gel detection reagent according to claim 1, wherein: the gel buffer solution contains 1-1.5 g of bovine serum albumin, 2-3 g of EDTA disodium and 0.2-0.4 g of PVP in every 100ml of PBS buffer solution, and the pH value of the gel buffer solution is 7.0.

6. The brucella antibody gel detection reagent according to claim 1, wherein: the volume ratio of the gel buffer to the antihuman globulin reagent is 1:1 to 7:1.

7. the brucella antibody gel detection reagent according to claim 1, wherein: the brucella antigen reagent is prepared by adding tiger red-dyed brucella antigen into PBS buffer solution, wherein the concentration of the tiger red-dyed brucella antigen is 1% -4%.